The main aim of the proposed work is to find out whether the cerebellar cortex of the anterior lobe responds to natural stimulation of macular labyrinthine receptors and whether the induced discharge of the corresponding Purkinje neurons is able to modify the reflex activity of Deiters' neurons evoked by macular stimulation. Attempts will also be made to find out whether the same corticocerebellar neurons integrate from time to time not only the command signals originating from macular receptors, but also the somatosensory input originating from neck and limb receptors, as a result of the actual displacement of the head occurring during the positional reflex. BIBLIOGRAPHIC REFERENCES: Corvaja N., Grofova I., Pompeiano O. and Walberg F. The lateral reticular nucleus in the cat. I. An experimental anatomical study of its spinal and supraspinal afferent connections. Neuroscience, 1977, in press. Pellegrini M., Pompeiano O. and Corvaja N. Identification of different size motoneurons labeled by the retrograde axonal transport of horseradish peroxidase. Pflugers Arch., 1977, in press.